Expansion-shield



L. R. ZIFFERER.

EXPANSION SHIELD.

APPLICATION FILED APR.2, 1919.

1,352,494. Patented Sept. 14,1920.

WITNESSES: 5 I AZVENTOR W Lamar/2? [,Zfffif' LOTHAR LR. ZIFFERER, OFLANCASTER, PENNSYLVANIA.

EXPANSION-SHIELD.

Specification of Letters Patent. Patented Sept. 14, 1920.

Application filed April 2, 1919.. Serial No. 286,848.

To all whom it may concern:

Be it known that I, LOTHAR R. ZIFFERER, a citizen of the United States,residing at Lancaster in the county of Lancaster and State ofiPennsylvania, have invented certain new and useful Improvements inExpansion-Shields, of which the followingis a specification.

This invention relates to an expansible shield consisting of two or moreparts, and. particularly to a means for connecting the shield parts, aswell as a means for insuring their initial expansion. It is customary inA. typical embodiment of this fastening is shown in the several figuresof the drawing wherem- Figure 1 represents in elevation a two-partexpansion shield of the indirect type equipped wlth my improvedfastening: means;

Fig. 2 is a longitudinal section through the shield inserted in anaperture the parts appearing as in the initial stage of expansion;

Fig. 8 is a similar view, showing the attaching bolt advanced againstthe work; and

Fig. at is a sectional detail of the fastening means employed.

I would have it understood that this invention in one of its phases atleast, is applicable to shields of the direct type wherein a boltengages directly with the tapering surfaces on the interior of theshield to cause expansion; or to a shield of the indirect type wherein anut engaging with the interior of the shield is adapted to be advancedlongitudinally by. means of the attaching bolt. With the indirect type,moreover, my invention is capable of a further use, as will presentlyappear.

Referring to the drawing, by way of illustration I have shown a shieldof two parts which are designated as 5 and 6. Interiorly these parts areformed to present tapering surfaces 7 and 8 respectively, against whicha nut 9 may lie and be advanced with rotaion of the attaching bolt 16.In Figs. 2

and 3, the device is shown as inserted within an aperture 11 which maybe formed in a wall or other structure, the work to be tight enedthereupon being designated by the nu meral 12. The exterior of theshield may be formed in any approved manner, it being desirable for thepresentpurposes that some sort of an annular rib or series ofprojections 13 be formed near the outer end.

Each shield section may be a counterpart of the other, and after beingassembled in operative relation, a band 14:, probably of sheet metal, isfitted around the shield over the rib l3. Initially this band may beformed with a flange 15 at one side (see Fig. 4:) arranged to abut theshield end, but upon being fitted in place, its other side 16 ispreferably crimped or turned in, as appears clearly in Figs. 2 and 3.The effect of this is to secure the'band upon the shield in anirremovable manner, so that the shield parts are held together in hingedrelation at their forward ends, being prevented from moving apart,sidewise, or endwise upon each other.

lVith shields of the indirect type, a cap 17 may be employed. toadvantage in the manner now to be described. This capsee Figs. 2 and3--is flanged as at 18 so as to be turned or crimped over an annularribor other projecting element 19 formed at the inner end of each shieldpart. When so positioned it serves as a closure to keep the nut 9 fromcoming out. It serves further as a wall or abutment for the extremity ofthe bolt so as to prevent in the initial stage of expansion, travel orthe bolt until after the nut has been advanced a SllfilClGIlt distanceto crowd apart the shield sections to a point where they frictionallyengage the walls of the aperture to resist turning therein. The effectof this action is to induce an early expansion such that the shield willquickly take hold of the wall. Having proceeded thus far, continuedrotation of the bolt will rupture the cap (see Fig. 3), so that its headwill tighten upon the work. As a condition precedent, it will be notedthat the shield parts must oifer greater resistance to the movement ofthe nut than will be offered by the cap to the continued travel of thebolt.

The structure shown is preferred, but changes are clearly possibleWithout departing from the principle of this invention which I nowdefine as follows.

I claim:

1. An expansion shield of the indirect type having a closure at itsinner end consisting of a cap fitted to the shield and forming afrangible abutment for the bolt, substantially as described.

in nature to aiford a temporary abutment 5 for the bolt, substantiallyas described.

L. R. ZIFFERER.

Witness W. T. HAMBRIGHT.

